docs/plugins/html/gst-plugins-base-plugins-appsink.html

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  24 <a href="#gst-plugins-base-plugins-appsink.synopsis" class="shortcut">Top</a>
  25                    |
  26                   <a href="#gst-plugins-base-plugins-appsink.description" class="shortcut">Description</a>
  27                    |
  28                   <a href="#gst-plugins-base-plugins-appsink.object-hierarchy" class="shortcut">Object Hierarchy</a>
  29                    |
  30                   <a href="#gst-plugins-base-plugins-appsink.implemented-interfaces" class="shortcut">Implemented Interfaces</a>
  31                    |
  32                   <a href="#gst-plugins-base-plugins-appsink.properties" class="shortcut">Properties</a>
  33                    |
  34                   <a href="#gst-plugins-base-plugins-appsink.signals" class="shortcut">Signals</a>
  35 </td></tr>
  36 </table>
  37 <div class="refentry">
  38 <a name="gst-plugins-base-plugins-appsink"></a><div class="titlepage"></div>
  39 <div class="refnamediv"><table width="100%"><tr>
  40 <td valign="top">
  41 <h2><span class="refentrytitle"><a name="gst-plugins-base-plugins-appsink.top_of_page"></a>appsink</span></h2>
  42 <p>appsink — Allow the application to get access to raw buffer</p>
  43 </td>
  44 <td valign="top" align="right"></td>
  45 </tr></table></div>
  46 <div class="refsynopsisdiv">
  47 <a name="gst-plugins-base-plugins-appsink.synopsis"></a><h2>Synopsis</h2>
  48 <a name="GstAppSink"></a><pre class="synopsis">struct              <a class="link" href="gst-plugins-base-plugins-appsink.html#GstAppSink-struct" title="struct GstAppSink">GstAppSink</a>;
  49 </pre>
  50 </div>
  51 <div class="refsect1">
  52 <a name="gst-plugins-base-plugins-appsink.object-hierarchy"></a><h2>Object Hierarchy</h2>
  53 <pre class="synopsis">
  54   <a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#GObject">GObject</a>
  55    +----<a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstObject.html">GstObject</a>
  56          +----<a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstElement.html">GstElement</a>
  57                +----<a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer-libs/html/GstBaseSink.html">GstBaseSink</a>
  58                      +----GstAppSink
  59 </pre>
  60 </div>
  61 <div class="refsect1">
  62 <a name="gst-plugins-base-plugins-appsink.implemented-interfaces"></a><h2>Implemented Interfaces</h2>
  63 <p>
  64 GstAppSink implements
  65  <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstUriHandler.html#GstURIHandler">GstURIHandler</a>.</p>
  66 </div>
  67 <div class="refsect1">
  68 <a name="gst-plugins-base-plugins-appsink.properties"></a><h2>Properties</h2>
  69 <pre class="synopsis">
  70   "<a class="link" href="gst-plugins-base-plugins-appsink.html#GstAppSink--caps" title='The "caps" property'>caps</a>"                     <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="type">GstCaps</span></a>*              : Read / Write
  71   "<a class="link" href="gst-plugins-base-plugins-appsink.html#GstAppSink--drop" title='The "drop" property'>drop</a>"                     <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a>              : Read / Write
  72   "<a class="link" href="gst-plugins-base-plugins-appsink.html#GstAppSink--emit-signals" title='The "emit-signals" property'>emit-signals</a>"             <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a>              : Read / Write
  73   "<a class="link" href="gst-plugins-base-plugins-appsink.html#GstAppSink--eos" title='The "eos" property'>eos</a>"                      <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a>              : Read
  74   "<a class="link" href="gst-plugins-base-plugins-appsink.html#GstAppSink--max-buffers" title='The "max-buffers" property'>max-buffers</a>"              <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint"><span class="type">guint</span></a>                 : Read / Write
  75 </pre>
  76 </div>
  77 <div class="refsect1">
  78 <a name="gst-plugins-base-plugins-appsink.signals"></a><h2>Signals</h2>
  79 <pre class="synopsis">
  80   "<a class="link" href="gst-plugins-base-plugins-appsink.html#GstAppSink-eos" title='The "eos" signal'>eos</a>"                                            : <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Signals.html#G-SIGNAL-RUN-LAST:CAPS"><code class="literal">Run Last</code></a>
  81   "<a class="link" href="gst-plugins-base-plugins-appsink.html#GstAppSink-new-buffer" title='The "new-buffer" signal'>new-buffer</a>"                                     : <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Signals.html#G-SIGNAL-RUN-LAST:CAPS"><code class="literal">Run Last</code></a>
  82   "<a class="link" href="gst-plugins-base-plugins-appsink.html#GstAppSink-new-preroll" title='The "new-preroll" signal'>new-preroll</a>"                                    : <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Signals.html#G-SIGNAL-RUN-LAST:CAPS"><code class="literal">Run Last</code></a>
  83   "<a class="link" href="gst-plugins-base-plugins-appsink.html#GstAppSink-pull-buffer" title='The "pull-buffer" signal'>pull-buffer</a>"                                    : <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Signals.html#G-SIGNAL-ACTION:CAPS"><code class="literal">Action</code></a>
  84   "<a class="link" href="gst-plugins-base-plugins-appsink.html#GstAppSink-pull-preroll" title='The "pull-preroll" signal'>pull-preroll</a>"                                   : <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Signals.html#G-SIGNAL-ACTION:CAPS"><code class="literal">Action</code></a>
  85   "<a class="link" href="gst-plugins-base-plugins-appsink.html#GstAppSink-new-buffer-list" title='The "new-buffer-list" signal'>new-buffer-list</a>"                                : <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Signals.html#G-SIGNAL-RUN-LAST:CAPS"><code class="literal">Run Last</code></a>
  86   "<a class="link" href="gst-plugins-base-plugins-appsink.html#GstAppSink-pull-buffer-list" title='The "pull-buffer-list" signal'>pull-buffer-list</a>"                               : <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Signals.html#G-SIGNAL-ACTION:CAPS"><code class="literal">Action</code></a>
  87 </pre>
  88 </div>
  89 <div class="refsect1">
  90 <a name="gst-plugins-base-plugins-appsink.description"></a><h2>Description</h2>
  91 <p>
  92 Appsink is a sink plugin that supports many different methods for making
  93 the application get a handle on the GStreamer data in a pipeline. Unlike
  94 most GStreamer elements, Appsink provides external API functions.
  95 </p>
  96 <p>
  97 For the documentation of the API, please see the
  98 <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base-libs/html/gst-plugins-base-libs-appsink.html">libgstapp</a> section in
  99 the GStreamer Plugins Base Libraries documentation.
 100 </p>
 101 <div class="refsynopsisdiv">
 102 <h2>Synopsis</h2>
 103 <div class="refsect2">
 104 <a name="idp9669776"></a><h3>Element Information</h3>
 105 <div class="variablelist"><table border="0">
 106 <col align="left" valign="top">
 107 <tbody>
 108 <tr>
 109 <td><p><span class="term">plugin</span></p></td>
 110 <td>
 111             <a class="link" href="gst-plugins-base-plugins-plugin-app.html#plugin-app">app</a>
 112           </td>
 113 </tr>
 114 <tr>
 115 <td><p><span class="term">author</span></p></td>
 116 <td>David Schleef &lt;ds@schleef.org&gt;, Wim Taymans &lt;wim.taymans@gmail.com&gt;</td>
 117 </tr>
 118 <tr>
 119 <td><p><span class="term">class</span></p></td>
 120 <td>Generic/Sink</td>
 121 </tr>
 122 </tbody>
 123 </table></div>
 124 </div>
 125 <hr>
 126 <div class="refsect2">
 127 <a name="idp9677184"></a><h3>Element Pads</h3>
 128 <div class="variablelist"><table border="0">
 129 <col align="left" valign="top">
 130 <tbody>
 131 <tr>
 132 <td><p><span class="term">name</span></p></td>
 133 <td>sink</td>
 134 </tr>
 135 <tr>
 136 <td><p><span class="term">direction</span></p></td>
 137 <td>sink</td>
 138 </tr>
 139 <tr>
 140 <td><p><span class="term">presence</span></p></td>
 141 <td>always</td>
 142 </tr>
 143 <tr>
 144 <td><p><span class="term">details</span></p></td>
 145 <td>ANY</td>
 146 </tr>
 147 </tbody>
 148 </table></div>
 149 </div>
 150 </div>
 151 <p>
 152 </p>
 153 </div>
 154 <div class="refsect1">
 155 <a name="gst-plugins-base-plugins-appsink.details"></a><h2>Details</h2>
 156 <div class="refsect2">
 157 <a name="GstAppSink-struct"></a><h3>struct GstAppSink</h3>
 158 <pre class="programlisting">struct GstAppSink;</pre>
 159 <p>
 160 </p>
 161 </div>
 162 </div>
 163 <div class="refsect1">
 164 <a name="gst-plugins-base-plugins-appsink.property-details"></a><h2>Property Details</h2>
 165 <div class="refsect2">
 166 <a name="GstAppSink--caps"></a><h3>The <code class="literal">"caps"</code> property</h3>
 167 <pre class="programlisting">  "caps"                     <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="type">GstCaps</span></a>*              : Read / Write</pre>
 168 <p>The allowed caps for the sink pad.</p>
 169 </div>
 170 <hr>
 171 <div class="refsect2">
 172 <a name="GstAppSink--drop"></a><h3>The <code class="literal">"drop"</code> property</h3>
 173 <pre class="programlisting">  "drop"                     <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a>              : Read / Write</pre>
 174 <p>Drop old buffers when the buffer queue is filled.</p>
 175 <p>Default value: FALSE</p>
 176 </div>
 177 <hr>
 178 <div class="refsect2">
 179 <a name="GstAppSink--emit-signals"></a><h3>The <code class="literal">"emit-signals"</code> property</h3>
 180 <pre class="programlisting">  "emit-signals"             <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a>              : Read / Write</pre>
 181 <p>Emit new-preroll, new-buffer and new-buffer-list signals.</p>
 182 <p>Default value: FALSE</p>
 183 </div>
 184 <hr>
 185 <div class="refsect2">
 186 <a name="GstAppSink--eos"></a><h3>The <code class="literal">"eos"</code> property</h3>
 187 <pre class="programlisting">  "eos"                      <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a>              : Read</pre>
 188 <p>Check if the sink is EOS or not started.</p>
 189 <p>Default value: TRUE</p>
 190 </div>
 191 <hr>
 192 <div class="refsect2">
 193 <a name="GstAppSink--max-buffers"></a><h3>The <code class="literal">"max-buffers"</code> property</h3>
 194 <pre class="programlisting">  "max-buffers"              <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint"><span class="type">guint</span></a>                 : Read / Write</pre>
 195 <p>The maximum number of buffers to queue internally (0 = unlimited).</p>
 196 <p>Default value: 0</p>
 197 </div>
 198 </div>
 199 <div class="refsect1">
 200 <a name="gst-plugins-base-plugins-appsink.signal-details"></a><h2>Signal Details</h2>
 201 <div class="refsect2">
 202 <a name="GstAppSink-eos"></a><h3>The <code class="literal">"eos"</code> signal</h3>
 203 <pre class="programlisting"><span class="returnvalue">void</span>                user_function                      (<a class="link" href="gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *appsink,
 204                                                         <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a>    user_data)      : <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Signals.html#G-SIGNAL-RUN-LAST:CAPS"><code class="literal">Run Last</code></a></pre>
 205 <p>
 206 Signal that the end-of-stream has been reached. This signal is emited from
 207 the steaming thread.
 208 </p>
 209 <div class="variablelist"><table border="0">
 210 <col align="left" valign="top">
 211 <tbody>
 212 <tr>
 213 <td><p><span class="term"><em class="parameter"><code>appsink</code></em> :</span></p></td>
 214 <td>the appsink element that emited the signal</td>
 215 </tr>
 216 <tr>
 217 <td><p><span class="term"><em class="parameter"><code>user_data</code></em> :</span></p></td>
 218 <td>user data set when the signal handler was connected.</td>
 219 </tr>
 220 </tbody>
 221 </table></div>
 222 </div>
 223 <hr>
 224 <div class="refsect2">
 225 <a name="GstAppSink-new-buffer"></a><h3>The <code class="literal">"new-buffer"</code> signal</h3>
 226 <pre class="programlisting"><span class="returnvalue">void</span>                user_function                      (<a class="link" href="gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *appsink,
 227                                                         <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a>    user_data)      : <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Signals.html#G-SIGNAL-RUN-LAST:CAPS"><code class="literal">Run Last</code></a></pre>
 228 <p>
 229 Signal that a new buffer is available.
 230 </p>
 231 <p>
 232 This signal is emited from the steaming thread and only when the
 233 "emit-signals" property is <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a>.
 234 </p>
 235 <p>
 236 The new buffer can be retrieved with the "pull-buffer" action
 237 signal or <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base-libs/html/gst-plugins-base-libs-appsink.html#gst-app-sink-pull-buffer"><code class="function">gst_app_sink_pull_buffer()</code></a> either from this signal callback
 238 or from any other thread.
 239 </p>
 240 <p>
 241 Note that this signal is only emited when the "emit-signals" property is
 242 set to <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a>, which it is not by default for performance reasons.
 243 </p>
 244 <div class="variablelist"><table border="0">
 245 <col align="left" valign="top">
 246 <tbody>
 247 <tr>
 248 <td><p><span class="term"><em class="parameter"><code>appsink</code></em> :</span></p></td>
 249 <td>the appsink element that emited the signal</td>
 250 </tr>
 251 <tr>
 252 <td><p><span class="term"><em class="parameter"><code>user_data</code></em> :</span></p></td>
 253 <td>user data set when the signal handler was connected.</td>
 254 </tr>
 255 </tbody>
 256 </table></div>
 257 </div>
 258 <hr>
 259 <div class="refsect2">
 260 <a name="GstAppSink-new-preroll"></a><h3>The <code class="literal">"new-preroll"</code> signal</h3>
 261 <pre class="programlisting"><span class="returnvalue">void</span>                user_function                      (<a class="link" href="gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *appsink,
 262                                                         <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a>    user_data)      : <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Signals.html#G-SIGNAL-RUN-LAST:CAPS"><code class="literal">Run Last</code></a></pre>
 263 <p>
 264 Signal that a new preroll buffer is available.
 265 </p>
 266 <p>
 267 This signal is emited from the steaming thread and only when the
 268 "emit-signals" property is <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a>.
 269 </p>
 270 <p>
 271 The new preroll buffer can be retrieved with the "pull-preroll" action
 272 signal or <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base-libs/html/gst-plugins-base-libs-appsink.html#gst-app-sink-pull-preroll"><code class="function">gst_app_sink_pull_preroll()</code></a> either from this signal callback
 273 or from any other thread.
 274 </p>
 275 <p>
 276 Note that this signal is only emited when the "emit-signals" property is
 277 set to <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a>, which it is not by default for performance reasons.
 278 </p>
 279 <div class="variablelist"><table border="0">
 280 <col align="left" valign="top">
 281 <tbody>
 282 <tr>
 283 <td><p><span class="term"><em class="parameter"><code>appsink</code></em> :</span></p></td>
 284 <td>the appsink element that emited the signal</td>
 285 </tr>
 286 <tr>
 287 <td><p><span class="term"><em class="parameter"><code>user_data</code></em> :</span></p></td>
 288 <td>user data set when the signal handler was connected.</td>
 289 </tr>
 290 </tbody>
 291 </table></div>
 292 </div>
 293 <hr>
 294 <div class="refsect2">
 295 <a name="GstAppSink-pull-buffer"></a><h3>The <code class="literal">"pull-buffer"</code> signal</h3>
 296 <pre class="programlisting"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstBuffer.html#GstBuffer"><span class="returnvalue">GstBuffer</span></a>*          user_function                      (<a class="link" href="gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *appsink,
 297                                                         <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a>    user_data)      : <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Signals.html#G-SIGNAL-ACTION:CAPS"><code class="literal">Action</code></a></pre>
 298 <p>
 299 This function blocks until a buffer or EOS becomes available or the appsink
 300 element is set to the READY/NULL state.
 301 </p>
 302 <p>
 303 This function will only return buffers when the appsink is in the PLAYING
 304 state. All rendered buffers will be put in a queue so that the application
 305 can pull buffers at its own rate.
 306 </p>
 307 <p>
 308 Note that when the application does not pull buffers fast enough, the
 309 queued buffers could consume a lot of memory, especially when dealing with
 310 raw video frames. It's possible to control the behaviour of the queue with
 311 the "drop" and "max-buffers" properties.
 312 </p>
 313 <p>
 314 If an EOS event was received before any buffers, this function returns
 315 <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>. Use <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base-libs/html/gst-plugins-base-libs-appsink.html#gst-app-sink-is-eos"><code class="function">gst_app_sink_is_eos()</code></a> to check for the EOS condition.
 316 </p>
 317 <div class="variablelist"><table border="0">
 318 <col align="left" valign="top">
 319 <tbody>
 320 <tr>
 321 <td><p><span class="term"><em class="parameter"><code>appsink</code></em> :</span></p></td>
 322 <td>the appsink element to emit this signal on</td>
 323 </tr>
 324 <tr>
 325 <td><p><span class="term"><em class="parameter"><code>user_data</code></em> :</span></p></td>
 326 <td>user data set when the signal handler was connected.</td>
 327 </tr>
 328 <tr>
 329 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 330 <td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstBuffer.html#GstBuffer"><span class="type">GstBuffer</span></a> or NULL when the appsink is stopped or EOS.</td>
 331 </tr>
 332 </tbody>
 333 </table></div>
 334 </div>
 335 <hr>
 336 <div class="refsect2">
 337 <a name="GstAppSink-pull-preroll"></a><h3>The <code class="literal">"pull-preroll"</code> signal</h3>
 338 <pre class="programlisting"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstBuffer.html#GstBuffer"><span class="returnvalue">GstBuffer</span></a>*          user_function                      (<a class="link" href="gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *appsink,
 339                                                         <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a>    user_data)      : <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Signals.html#G-SIGNAL-ACTION:CAPS"><code class="literal">Action</code></a></pre>
 340 <p>
 341 Get the last preroll buffer in <em class="parameter"><code>appsink</code></em>. This was the buffer that caused the
 342 appsink to preroll in the PAUSED state. This buffer can be pulled many times
 343 and remains available to the application even after EOS.
 344 </p>
 345 <p>
 346 This function is typically used when dealing with a pipeline in the PAUSED
 347 state. Calling this function after doing a seek will give the buffer right
 348 after the seek position.
 349 </p>
 350 <p>
 351 Note that the preroll buffer will also be returned as the first buffer
 352 when calling <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base-libs/html/gst-plugins-base-libs-appsink.html#gst-app-sink-pull-buffer"><code class="function">gst_app_sink_pull_buffer()</code></a> or the "pull-buffer" action signal.
 353 </p>
 354 <p>
 355 If an EOS event was received before any buffers, this function returns
 356 <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>. Use <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base-libs/html/gst-plugins-base-libs-appsink.html#gst-app-sink-is-eos"><code class="function">gst_app_sink_is_eos()</code></a> to check for the EOS condition.
 357 </p>
 358 <p>
 359 This function blocks until a preroll buffer or EOS is received or the appsink
 360 element is set to the READY/NULL state.
 361 </p>
 362 <div class="variablelist"><table border="0">
 363 <col align="left" valign="top">
 364 <tbody>
 365 <tr>
 366 <td><p><span class="term"><em class="parameter"><code>appsink</code></em> :</span></p></td>
 367 <td>the appsink element to emit this signal on</td>
 368 </tr>
 369 <tr>
 370 <td><p><span class="term"><em class="parameter"><code>user_data</code></em> :</span></p></td>
 371 <td>user data set when the signal handler was connected.</td>
 372 </tr>
 373 <tr>
 374 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 375 <td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstBuffer.html#GstBuffer"><span class="type">GstBuffer</span></a> or NULL when the appsink is stopped or EOS.</td>
 376 </tr>
 377 </tbody>
 378 </table></div>
 379 </div>
 380 <hr>
 381 <div class="refsect2">
 382 <a name="GstAppSink-new-buffer-list"></a><h3>The <code class="literal">"new-buffer-list"</code> signal</h3>
 383 <pre class="programlisting"><span class="returnvalue">void</span>                user_function                      (<a class="link" href="gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *appsink,
 384                                                         <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a>    user_data)      : <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Signals.html#G-SIGNAL-RUN-LAST:CAPS"><code class="literal">Run Last</code></a></pre>
 385 <p>
 386 Signal that a new bufferlist is available.
 387 </p>
 388 <p>
 389 This signal is emited from the steaming thread and only when the
 390 "emit-signals" property is <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a>.
 391 </p>
 392 <p>
 393 The new buffer can be retrieved with the "pull-buffer-list" action
 394 signal or <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base-libs/html/gst-plugins-base-libs-appsink.html#gst-app-sink-pull-buffer-list"><code class="function">gst_app_sink_pull_buffer_list()</code></a> either from this signal callback
 395 or from any other thread.
 396 </p>
 397 <p>
 398 Note that this signal is only emited when the "emit-signals" property is
 399 set to <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a>, which it is not by default for performance reasons.
 400 </p>
 401 <div class="variablelist"><table border="0">
 402 <col align="left" valign="top">
 403 <tbody>
 404 <tr>
 405 <td><p><span class="term"><em class="parameter"><code>appsink</code></em> :</span></p></td>
 406 <td>the appsink element that emited the signal</td>
 407 </tr>
 408 <tr>
 409 <td><p><span class="term"><em class="parameter"><code>user_data</code></em> :</span></p></td>
 410 <td>user data set when the signal handler was connected.</td>
 411 </tr>
 412 </tbody>
 413 </table></div>
 414 </div>
 415 <hr>
 416 <div class="refsect2">
 417 <a name="GstAppSink-pull-buffer-list"></a><h3>The <code class="literal">"pull-buffer-list"</code> signal</h3>
 418 <pre class="programlisting"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstBufferList.html#GstBufferList"><span class="returnvalue">GstBufferList</span></a>*      user_function                      (<a class="link" href="gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *appsink,
 419                                                         <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a>    user_data)      : <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Signals.html#G-SIGNAL-ACTION:CAPS"><code class="literal">Action</code></a></pre>
 420 <p>
 421 This function blocks until a buffer list or EOS becomes available or the appsink
 422 element is set to the READY/NULL state.
 423 </p>
 424 <p>
 425 This function will only return bufferlists when the appsink is in the PLAYING
 426 state. All rendered bufferlists will be put in a queue so that the application
 427 can pull bufferlists at its own rate.
 428 </p>
 429 <p>
 430 Note that when the application does not pull bufferlists fast enough, the
 431 queued bufferlists could consume a lot of memory, especially when dealing with
 432 raw video frames. It's possible to control the behaviour of the queue with
 433 the "drop" and "max-buffers" properties.
 434 </p>
 435 <p>
 436 If an EOS event was received before any buffers, this function returns
 437 <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>. Use <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base-libs/html/gst-plugins-base-libs-appsink.html#gst-app-sink-is-eos"><code class="function">gst_app_sink_is_eos()</code></a> to check for the EOS condition.
 438 </p>
 439 <div class="variablelist"><table border="0">
 440 <col align="left" valign="top">
 441 <tbody>
 442 <tr>
 443 <td><p><span class="term"><em class="parameter"><code>appsink</code></em> :</span></p></td>
 444 <td>the appsink element to emit this signal on</td>
 445 </tr>
 446 <tr>
 447 <td><p><span class="term"><em class="parameter"><code>user_data</code></em> :</span></p></td>
 448 <td>user data set when the signal handler was connected.</td>
 449 </tr>
 450 <tr>
 451 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 452 <td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstBufferList.html#GstBufferList"><span class="type">GstBufferList</span></a> or NULL when the appsink is stopped or EOS.</td>
 453 </tr>
 454 </tbody>
 455 </table></div>
 456 </div>
 457 </div>
 458 </div>
 459 <div class="footer">
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